Biotin absorption and metabolism

Biotin is absorbed in the small intestine and any excess is excreted in the urine. Normally, the amount of biotin excreted in the urine and feces is up to six times greater than the amount eaten in food. This is due to the large quantities produced by gut bacteria.

Biotin is available commercially as isolated biotin or as a complex in brewer's yeast. There have been no reported toxic effects even at large doses.